Processes for preparing N-substituted salicylamides are known such as that shown in Scheme 1.

The oligosalicylate is obtained from the corresponding salicylic acid upon treatment with acetic anhydride. Coupling of the amino acid is promoted with a base, preferably potassium carbonate in a suitable solvent (like dioxane). Yields are generally in the order of 50%.
An exemplary compound synthesised by this prior art process is 5-CNAC, which is commonly used as a delivery agent for therapeutic agents and is used in pharmaceutical compositions.